1. Technical Field
The present invention relates to an angular velocity sensor, an electronic apparatus, and a moving object.
2. Related Art
Angular velocity sensors detecting an angular velocity are used for, for example, body control in vehicles, host vehicle position detection of car navigation systems, and vibration control correction (so-called camera shake correction) of digital cameras, video cameras, and the like. For example, a vibration gyro sensor is known as such an angular velocity sensor (for example, see JP-A-2001-194157).
For example, an angular velocity sensor disclosed in JP-A-2001-194157 includes a vibrating body which is supported with respect to a frame body through a vibrating body supporting beam. In the angular velocity sensor, when an angular velocity around a z-axis is applied from the outside in a state where the vibrating body is vibrated (driving vibration) in an x-axis direction, a Coriolis force acts on the vibrating body, and thus the vibrating body is displaced (detection vibration) in a y-axis direction. Then, the angular velocity around the z-axis is detected by detecting the amount of displacement of the vibrating body in the y-axis direction.
Incidentally, in addition to an angular velocity to be detected, an impact from the outside may be applied to such an angular velocity sensor, and thus there is a concern that vibration occurring due to the impact may degrade detection accuracy and the like.
Consequently, in the angular velocity sensor disclosed in JP-A-2001-194157, the frame body is supported with respect to a supporting unit through a frame body supporting beam, and the frame body and the frame body supporting beam constitute an impact attenuation mechanism that attenuates the transmission of an impact along at least one of a vibration direction and a detection direction of the vibrating body to the vibrating body from the supporting unit. Thus, even when a waveform of an impact applied to the angular velocity sensor includes vibration close to a resonance frequency of the vibrating body in the vibration direction and the detection direction of the vibrating body, it is possible to suppress the influence on detection accuracy.
However, when rotational vibration around a y-axis is applied, the angular velocity sensor disclosed in JP-A-2001-194157 cannot attenuate the rotational vibration. For this reason, when rotational vibration including a frequency component near a detuning frequency (difference between a resonance frequency in a driving vibration mode and a resonance frequency in a detection vibration mode) is applied, for example, due to the resonance of a substrate on which a sensor is mounted, an unexpected signal is generated due to the resonance of the detection vibration, and the signal is saturated within an IC for processing the signal. As a result, there is a problem in that an output fluctuates.